In the days that followed, Alan dove into the modification and optimization of his new spells the moment his classes ended. Having already navigated the development process for his previous two charms, he encountered few obstacles and quickly refined the original sequences into four distinct rune combinations.
By the end of October, he began intensive field testing. His methodology was systematic, divided into two primary phases. The first was a safety check to ensure the spell wasn't inherently toxic or volatile when cast near living organisms. At this stage, a mouse would make its appearance; Alan would cast the spell on the subject several times and observe it for any physical abnormalities. If the mouse remained healthy, he proceeded. This extra precaution was a direct result of nearly killing himself during his last reckless experiment; for his own safety, he made it a mandatory step for all future research.
The second phase was the actual measurement of the effect. He named his modified creation the Sound Wave Repulsion Spell. He began by casting it on himself and listening to the ambient sounds of the Forbidden Forest. When he found he couldn't hear the rustle of the trees or the wind, he increased the power and had Hagrid shout at him from a few yards away. Once the spell proved effective against audible noise, he moved on to the Echo Spell. Since ultrasound operates at a very high frequency, he reasoned that if the shield could block those waves, it could block almost anything.
Finally, he prepared to face the infrasonic frequency once more.
*All four combinations can block natural sound,* Alan noted after the initial trials. *But only the third set completely isolates the ultrasound. I'll use that as the foundation for the final version.*
He did not rush back into the infrasonic experiment. He had no desire to relive the agony of being attacked by his own magic, so he spent several more days fine-tuning the third rune set. He was determined to have every variable controlled before the final test.
"Time: October 31st, 7:38 PM. Second infrasonic test beginning."
It was Halloween, and Hogwarts had prepared a lavish feast for the students, complete with ghost performances and enchanted decorations, but Alan had no interest in the festivities. He had spent the afternoon prepping, even brewing two restorative potions for himself just in case. He asked Hagrid to keep watch from a safe distance so the giant could intervene if something went wrong.
Alan took a deep breath, settling his mind into a state of absolute calm. He drew his wand, aimed it at himself, and cast his newly perfected Sound Wave Repulsion Spell.
"Ah! Hello! Testing!" Alan shouted. He heard nothing. Satisfied with the silence, he immediately transitioned to the infrasonic sequence. With a sharp flick of his wrist, the runes condensed at the tip of his wand, and a surge of magical power rippled outward.
Alan felt nothing. No nausea, no ringing, no bone-deep vibration. For a moment, he actually doubted the spell had worked at all. He cancelled the repulsion charm and looked at the cage beside him. The mouse was dead, bleeding from its nose and ears exactly like the previous subject.
"It worked. The shield actually held," Alan whispered, his voice sounding strangely loud in the quiet night. He was emboldened by the success and decided to push the experiment further, testing the effective range of the infrasonic waves.
As he was resetting the equipment, Hagrid suddenly ran toward him, waving his arms and shouting something. Alan, still shielded by his repulsion spell, couldn't hear a word. He quickly dispelled the barrier.
"What is it, Hagrid? I couldn't hear you."
"I have to go, Alan! Dumbledore just sent word—I've got to find him right away!" Hagrid looked frantic. He gripped his pink umbrella tightly and hurried off toward the castle without another word of explanation.
Alan watched him disappear into the shadows, wondering what could have caused such a sudden departure. He shook his head; whatever it was, it was likely headmaster business. He turned back to his cage of mice.
"The effect attenuates with distance," Alan noted, scribbling in his ledger. "Within five meters, it's lethal and the interference is absolute. Between five and ten meters, the lethality drops, but the disruption to the nervous system is still significant."
He looked at a mouse thirty meters away. Under the influence of the spell, the creature was merely squealing and scurrying nervously around its cage.
"Humans likely have a higher natural resistance. Beyond ten meters, the interference probably drops to a manageable level," he summarized.
By the time he finished the long-awaited experiment, Alan felt a deep sense of satisfaction, as if he had solved an impossible equation. Exhausted but triumphant, he returned to the cabin, climbed into bed, and fell into a dreamless sleep. He had no idea that while he was measuring sound waves in the forest, a tectonic shift was occurring in the wizarding world.
The next morning was a weekend. Alan completed his morning exercises and met an energetic Charles to head up to the Great Hall for breakfast.
The moment they walked in, they realized the atmosphere was electric. Hardly anyone was eating; the students were gathered in tight clusters, whispering and shouting in equal measure. The sky above the tables was thick with owls delivering special editions of the newspapers.
"Alan! Over here!" Vivian shouted, waving him over to the Slytherin table.
"What's going on? Why is everyone acting so strange?" Alan asked, sliding into a seat.
"You haven't heard?" Vivian looked at him, her eyes wide with shock. "He-Who-Must-Not-Be-Named has fallen! They're saying he was killed by a baby—the Boy Who Lived! The Daily Prophet put out an extra edition this morning, and my parents sent an owl to confirm it."
"What?" Alan felt a jolt of recognition. He snatched the newspaper from her hand, his eyes scanning the headlines. It had happened. The date he had been waiting for—the end of the first war—was finally here.